diff --git a/typo3/sysext/backend/Classes/Template/DocumentTemplate.php b/typo3/sysext/backend/Classes/Template/DocumentTemplate.php
index ded79e52530cb3df173c341e7d7dd546f803394d..a02a43bf5c026b64e41329197edb9a5aa5ba13d0 100644
--- a/typo3/sysext/backend/Classes/Template/DocumentTemplate.php
+++ b/typo3/sysext/backend/Classes/Template/DocumentTemplate.php
@@ -1115,7 +1115,11 @@ function jumpToUrl(URL) {
 		if ($this->styleSheetFile2) {
 			$this->pageRenderer->addCssFile($this->backPath . $this->styleSheetFile2);
 		}
-		$this->pageRenderer->addCssInlineBlock('inDocStyles', $inDocStyles . LF . '/*###POSTCSSMARKER###*/');
+
+		if ($inDocStyles !== '') {
+			$this->pageRenderer->addCssInlineBlock('inDocStyles', $inDocStyles . LF . '/*###POSTCSSMARKER###*/');
+		}
+
 		if ($this->styleSheetFile_post) {
 			$this->pageRenderer->addCssFile($this->backPath . $this->styleSheetFile_post);
 		}